Well, it is unusual. The only other explanation I can think of is that perhaps, as her body was small and lean, and if animals had opened up sufficient areas, the fluids evaporated in the dry air, rather than seeping down into the ground. I have no experience with such a case, though, and it still seems to me there would have been at least some drainage from the pelvic area. *CAPPSMADNESS: What do you think?
Anyway, in thinking about to describe how the fluids are produced, etc., it seemed to gross... so I looked up a web site for anyone interested in such:
http://www.dundee.ac.uk/forensicmedicine/llb/timedeath.htm